From nobody Sun Dec 28 02:43:12 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 03A36C4332F for ; Wed, 13 Dec 2023 18:21:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1442399AbjLMSVO (ORCPT ); Wed, 13 Dec 2023 13:21:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52480 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235446AbjLMSUg (ORCPT ); Wed, 13 Dec 2023 13:20:36 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3457212E for ; Wed, 13 Dec 2023 10:20:39 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C8E96C433CA; Wed, 13 Dec 2023 18:20:38 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.97) (envelope-from ) id 1rDTrI-00000002a9H-0piW; Wed, 13 Dec 2023 13:21:24 -0500 Message-ID: <20231213182123.973261257@goodmis.org> User-Agent: quilt/0.67 Date: Wed, 13 Dec 2023 13:17:44 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Tzvetomir Stoyanov , Vincent Donnefort , Kent Overstreet Subject: [PATCH v3 07/15] ring-buffer: Do no swap cpu buffers if order is different References: <20231213181737.791847466@goodmis.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: "Steven Rostedt (Google)" As all the subbuffer order (subbuffer sizes) must be the same throughout the ring buffer, check the order of the buffers that are doing a CPU buffer swap in ring_buffer_swap_cpu() to make sure they are the same. If the are not the same, then fail to do the swap, otherwise the ring buffer will think the CPU buffer has a specific subbuffer size when it does not. Signed-off-by: Steven Rostedt (Google) --- kernel/trace/ring_buffer.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index ea3c217e4e43..2c908b4f3f68 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -5559,6 +5559,9 @@ int ring_buffer_swap_cpu(struct trace_buffer *buffer_= a, if (cpu_buffer_a->nr_pages !=3D cpu_buffer_b->nr_pages) goto out; =20 + if (buffer_a->subbuf_order !=3D buffer_b->subbuf_order) + goto out; + ret =3D -EAGAIN; =20 if (atomic_read(&buffer_a->record_disabled)) --=20 2.42.0